a) Field of the Invention
The invention is directed to a method for manufacturing a tank with an opening and with a device for damping a sloshing or splashing movement. The invention is further directed to this tank.
b) Description of the Related Art
When automobiles are accelerated or braked, the fuel normally splashes in the tank. This produces annoying noises in that the fuel that is set in motion strikes against the inner side of the tank and especially also against the upper side of the tank. Such noises are often perceived as annoying and should therefore be minimized.
It is known to fasten acoustic padding comprising an eight-layer knitted fabric inside the tank in the area of the upper side and wall of the tank. In this way, splash-restraining values ranging from good to satisfactory have previously been achieved. A disadvantage in this measure is the complicated mounting of the padding, especially when it must be carried out manually.
Installation generally turns out to be complicated because the padding, whose dimensions typically range from approximately 300 mm to 550 mm, must be introduced into the tank at the upper side through an opening in the tank which usually has a diameter of only 120 mm at most and must be secured at fastening bolts which are arranged specifically for this purpose. A further work step consists in providing the acoustic padding with extra holes for this purpose. On the whole, it is very complicated to provide a device of this kind for damping splashing noises.
Further, it is disadvantageous that, in this type of installation, splashing noises generally depend on the fill level because the noises originate in different areas of the tank, but the tank cannot be completely lined using this method. A complete lining of these areas is impossible because of the quantity of fastening bolts which would be needed for this purpose and which would compromise the strength of the tank. Therefore, splashing noises are still produced at certain fill levels. Subsequent installation steps in the form of blades or other kinds of flow interrupters achieve only unsatisfactory results because of the, at present, commonly used methods of manufacturing tanks as blown polyethylene tanks.
However, splashing does not only result in unwanted noises; in the case of highly explosive materials such as nitroglycerin, a splashing movement can also cause self-ignition. Thus, splashing movement should also be damped as far as possible in tanks used for transporting such materials.